Episode 45 of "Sabrina, the teenage witch"
s02e21 Fear Strikes Up A Conversation

Sabrina is chosen to read her essay on learning math to the school assembly, and at first doesn't understand why everyone else assumes that she is nervous about it... then, when stage fright finally hits, uses Salem's suggestion of a "fear removal" spell. But she hasn't heeded the warning from Franklin Delano Roosevelt (via her witches' manual), and her fear spreads contagiously through the school: Val and Mr. Kraft become paranoid, Harvey is terrified of sports injuries, Mrs. Quick becomes hysterically hypochondriacal, and Libby is horrorstruck at the thought of never winning another seasonal beauty pageant. The only solution is to banish Sabrina's externalized emotion into the Other Realm, where she must confront the forest of her subconscious fears. Meanwhile, Zelda and Hilda face another public ordeal when an overworked Zelda "snaps" from overwork just before she is due to present her scientific paper to a witchly symposium, leaving Hilda to attempt to be "the responsible one" for once.